There is a need for an insulated container which can be quickly and easily opened and closed and which can be carried in the pocket or in a purse to carry medicines or other perishables which require cooling, such as insulin for the diabetic. It is well-known that insulin must be kept at a temperature below normal room and body temperatures during the time that it is stored, and this raises a considerable problem for diabetic persons who travel. To carry an unprotected insulin bottle on the person is to expose it to much higher storage temperatures than can be tolerated. It is therefore necessary to provide an insulated container and closure in which such insulin can be safely carried without raising its temperature above permissable levels.
This problem has been recognized in Jentis et al U.S. Pat. No. 3,148,515 which shows a travelling kit for diabetics having an insulin storage compartment which can be cooled by the slow escape of a compressed gas to produce a refrigeration effect, the kit being, however, too large and cumbersome to be easily carried in anything smaller than a suitcase. Another diabetic's emergency kit is shown in Renn U.S. Pat. No. 2,740,516, which also stores other apparatus but is unrefrigerated and uninsulated.
U.S. Pat. No. 3,807,194 to Bond shows a thermal container whose structure is more similar to the wall construction of the present invention in that it includes inner and outer spaced rigid walls which are filled with an insulating foam, the lid being screwed onto the container in this showing.
U.S. Pat. No. 3,741,382 to Larimer shows a bottle packed in an insulating container which is apparently more concerned with shock than heat transfer, and shows a container fitted to receive a particular bottle. Southwick U.S. Pat. No. 3,472,568 also is fitted to receive and support a particular shape of bottle. U.S. Pat. No. 2,977,014 to Kock shows an insulated container supporting an ampoule.
There are of course many plastic containers in which the lid is shaped to seal on some sort of tongue, of which U.S. Pat. No. 2,766,796 to Tupper is an example.